1. Field of the Invention
The present invention generally relates to an inspecting method and apparatus and, more particularly, to a method and an apparatus for inspecting radio frequency identification (RFID) tags by determining whether there is any malfunctional RFID tag and then determining where the malfunctional RFID tag is located using a way of shielding.
2. Description of the Prior Art
Since 2004, the radio frequency identification (RFID) technology has become one of the top 10 breakthrough technologies of the century. The RFID technology has been widely used in, for example, logistics, inventory management, national securities, medical science and public health.
The RFID technology using a reader, RFID tags and middleware and system integration is characterized in that the reader issues radio waves at a specific frequency to the RFID tags to drive the circuitry in the RFID tags to transmit the data in the chip back to the reader.
An RFID tag comprises an RF integrated circuit (RFIC) and an antenna. An RFID tag is packaged using an an-isotropic conductive paste (ACP) to agglutinate the substrate of the antenna so that the conductive particles in the an-isotropic conductive paste complete the electric circuit. The packaging quality depends on the packaging temperature, the packaging pressure and the packaging time. Therefore, automatized detection after packaging is crucial in quality control and yield improvement when mass production is concerned.
Please refer to FIG. 1A and FIG. 1B, which are two examples of conventional apparatuses for inspecting RFID tags. In FIG. 1A, the apparatus 1a comprises a carriertape transportation device 10, a reading device 11 and a moving device 12. The carriertape transportation device 10 transports a carriertape 101 carrying a plurality of RFID tags 1011. The reading device 11 is disposed on one side of the carriertape 101. The reading device 11 comprises a reader 111 covered by a shelter 110 having an opening allowing the reader to read the data in a single RFID tag at a time. The moving device 12 is connected to the reading device 11 so as to drive the reading device 11 to move. In the apparatus 1a in FIG. 1A, the reading device 11 is moved so as to inspect an RFID tag at a time to determine whether there is any malfunctional RFID tag 1012. Even though the apparatus 1a is capable of inspecting every RFID tag, the reading device 11 has problems because of its large size, difficulty in carrying, difficulty in designing the readable zone and time-consuming inspection.
In FIG. 1B, the apparatus 1b also comprises a carriertape transportation device 10 and a reading device 13 that are similar to those of the apparatus 1a in FIG. 1A. However, reading device 13 of the apparatus 1b is not movable. Instead, the carriertape transportation device 10 sequentially moves so that the reading device 13 inspects an RFID tag at a time to determine whether there is any malfunctional RFID tag 1012, as disclosed in U.S. Pat. No. 6,104,291. Even though the apparatus 1b is capable of inspecting every RFID tag, there are problems because it is difficult to design the readable zone and time-consuming in inspection.
Therefore, there is need in providing a method and an apparatus for inspecting radio frequency identification (RFID) tags to overcome the afore-mentioned problems.